|
ITEM
|
First grade
|
Second Grade
|
|
Colour Index
|
10 max
|
20 max
|
|
Purity
|
90% min
|
85% min
|
|
Sulphate as SO4
|
0.001% max
|
0.002% max
|
|
Chloride as CL
|
0.003% max
|
0.005% max
|
|
Iron as FE
|
0.0001%max
|
0.0005%max
|
|
Evaporation residue
|
0.006% max
|
0.02% max
|
